Controlling means for electric motors.



No. 806,777. PA-TENTED DEC. 12, 1905. c. M. CLARK.

CONTROLLING MEANS FOR ELECTRIC MOTORS.

APPLIOATION I'ILED JULY 7, 1903.

W jzj MW CHARLES M. CLARK, OF SOUTH ORANGE, NEW JERSEY.

CONTROLLING MEANS FOR ELECTRIC MOTORS.

Specification of Letters Patent.

Patented Dec. 12, 1905.

Application filled July 7. 1903. Serial No. 164,558.

To all whom, it may concern:

Be it known that I, CHARLES M. CLARK, a citizen of the United States, and a resident of South Orange, New Jersey, have invented certain new and useful Improvements in (Jontrolling Means for Electric Motors, of which the following is a specification.

My invention relates to means for controlling and operating combined telphers and hoists, such as that shown in patent to Harding, No. 716,033, in which the current is supplied to the hoisting and telpher motors'from separate lines.

In the drawings forming part of this specification, Figure 1 is a diagram showing the general features of my invention. Fig. 1 is a view showing the safety-switch and connections when the hoisting-motor is in position to hoist the load. Fig. 2 is an elevation of the switch-operating device. Fig. 3 is a detail showing the same in one of its positions. Fig. 4 is a view showing the means by which the switch H is raised on the completion of the hoisting movement.

A represents any source of electrical energy from which runs the usual supply-wire B into a resistance-box C ofthe usual character.

K represents the telpher-motor, having a reversing-switch K.

L represents the hoisting-motor, having the reversing-switch L.

M represents a safety-switch, which when the hoist is in the act of lowering the load forms a part of the circuit through the hoisting-motor and which when the motor rises breaks the circuit through said motor. These 1 switches are of such a character that they are operated by a solenoid N upon the breaking of the circuit, as will be hereinafter more fully described.

The circuit through the telpher-motor is through the wire I, reversing-switch K, through wire I to and through the motor, through wire I to the other contacts of the reversing-switch, through wire I, through the solenoid N, through return-wire I and back to the cable J. r

The circuit through the hoisting-motor is from the contact G, through the wire H, to the circuit-breaking device H. This is a pivoted lever, which is normally held in contact with the contact piece H by means of a spring 0, as clearly shown in the diagram. From this contact-breaking device the circuit divides, one part going through the wire H to the safety-switch M and through returnwire H from said safety-switch to the contact-piece H The other circuit passes through the wire H to and through the switch L by wire H through the motor L, and by wire H to the contacts on the switch by wire H to the switch-operating solenoid N, and thence through the wire I to the cable J.

Referring to the diagram in Fig. 1, the motor has reached the predetermined place and has been stopped by throwing the switch in the position shown; but in throwing the switch the circuit has of course been broken, and, as hereinafter explained, the switch-operating device has moved the switches KI L in the position shown in said diagram, this position being such that upon completion of the circuit the hoisting-motor will operate to lower the load.

Upon contact being made with G the circuit willbe established through the hoistingmotor to lower the load, for the circuit is completed both through the safety-switch M and the branch from the contact-piece H When the load has reached its lowest position. the contact is broken at G and immediately the switches are again reversed and the safetyswitch placed in the position where the circuit through it is broken, as indicated in Fig. 1, though contact through the motor is maintained by the branch circuit from H Contact is again made at G, whereupon the motor operates to hoist the carrier or the load. When the carrier has reached its highest position, it lifts the circuit-breaking device H, thus breaking the circuit through the hoisting-motor and automatically stopping the same by the means illustrated in Fig. 4. This consists of a disk m, attached to the hoistingrope n, and so placed that it will bear against the lever H and raise the same when the load has reached a predetermined point. At the same time the switch operating mechanism works to reverse all the switches, placing the safety-switch M in position to establish the circuit through the hoisting-motor. If now the contact be maintained through G, the

hoist will again operate to lower the carrier;

but it will be observed that the motor cannot again operate to hoist until the circuit-breaking device H has been restored to its normal position, for upon reversing the hoisting-motor by breaking the contact the safety-switch M is again moved to break the circuit through it, as shown in Fig. 1. Consequently if the contact-breaking piece H is still raised the circuit through the hoisting-motor is entirely broken. It will thus be seen that it is impossible for the motor to raise its load too high, and thus I avoid all the danger of breaking or carrying away of the parts. It will be observed that while in making the circuit through the hoisting-motor the reversingswitch of the telpher-motor is also operated. That is of no importance, for if upon making contact with F the telpher starts to move in the wrong direction it is necessary only to break the circuit and close it again, thus operating the automatic switch-moving device, causing the telpher to move in the proper direction.

I will now describe in detail the switchoperating mechanism and the switch itself.

The reversing-switches K L are of the usual type and their operation need not be minutely described. They are both mounted on the same shaft 0, and on this shaft also is mounted the safety-switch M. This safetyswitch consists of a disk having metallic contacts at P and Q. These contact-pieces are connected by a conducting-piece R, the balance of the disk being formed of insulating material, so that when M is turned a quarter of a turn from the position shown in Fig. 1 no current can pass therethrough. If turned another quarter of a turn, the circuit will be again established, and so on. This shaft 0 is supported from the mechanism in any suitable way, as by a framework S. Supported on the shaft is a disk T, having pins 6. Attached to the mechanism also is a solenoid N, which has cores 0 0, these cores being connected at their lower ends by a connecting-piece (Z. To this connecting-piece is also attached a lug e, to which is pivoted the operating-rod f. This operating-rod has on one side a triangularlyshaped piece g, which has a slanting surface on one side and a ledge on the other of such shape as to bear against one of the pins 6 to move the same. At the lower end it is provided with a locking-hook h, the use of which will be hereinafter described. Attached to this rod at one end and to-some other suitable part of the mechanism at the other is a spring a}.

To hold the switch locked in position, I provide locking-pawls Z. 70 is normally kept in the position shown in Fig. 3 by means of the spring k. Z is normally kept in the position shown in the figure by the spring Z. The locking-pawl 7c bears against one of the pins 6, preventing movement toward the right. The pawl Z is provided with a lug Z which engages with another pin, as clearly shown, prevent ing movement toward the left- I The operating-bar f is provided with a pin f, so placed as to bear against the end of the pawl Z when the bar rises.

The operation of the device is as follows: Suppose the current be established through either one of the motors. As seen from the diagram in Fig. 1, the solenoid N becomes energized, thus raising the cores 0, which carry with them the operating-bar f. As this bar rises the pin f lifts the locking-pawl Z, and the pin 6 engaging the slanting surface on the part g swings the operating-bar to the left until it passes said pin, whereupon it again swings to the right, engaging said pin, as clearly shown in Fig. 3. At the same time the hook It engages underneath another pin 6, thus operating itself as a locking device to prevent movement toward the left. This is clearly shown in Fig. 3. If now the circuit be broken, the solenoid becomes deenergized and the spring pulls down the operating-bar f and, as will be seen by reference to Fig. 3, turns the shaft carrying the switches one-quarter of a turn in the direction shown by the arrow, thus reversing the switches. The locking-pawls, as will be seen, swing into place automatically, locking the switch against motion, and the whole device is then ready to be again operated, as described. By this means it will be seen that the switch is continuously operated at every break in the circuit, always in one direction, and is locked in position at all times when not being moved.

What I claim, and desire to secure by Let,- ters Patent, is

l. The combination of the telpher and hoist ing motors receiving current from different lines, a single switch and connections for operating either of said motors, and means for automatically reversing both motors when the circuit is broken at any point, substantially as described.

2. The combination of a hoisting-motor and connections for supplying current thereto, means for breaking the circuit through saidmotor when it is operated in the hoisting direction to a predetermined point, and automatic means for reversing said motor when it has reached said point, substantially as described.

3. The combination of a hoisting-motor and connections for supplying current thereto, a circuit-breaker in said connections adapted to be operated and break the circuit when the hoist has reached a predetermined point, an automatic safety switch operated by the breaking of said circuit to complete the circuit through the motor in the downward direction, substantially as described.

4:. The combination of a hoisting-motor and connections for supplying current thereto, a circuit-breaker in said circuit adapted to be operated by the hoist when it has reached a predetermined point, and means to prevent the circuit being established through said motor in the hoisting direction until said circuitbreaker is in its normal position, substantially as described. 7

5. The combination of a telpher-motor, a hoisting-motor, a circuit for supplying current thereto, automatic switches for each motor adapted to be operated upon the breaking of the circuit, and a safety-switch adapted to be operated simultaneously with said aforementioned switches, substantially as described.

6. The combination of a telpher-motor, a hoisting-motor, a circuit for supplying current thereto, automatic switches for each motor adapted to be operated upon the breaking of the circuit, a safety-switch forming part of said circuit, and a single operative means for simultaneously actuating all of said switches upon the breaking of the circuit, substantially as described.

7. The combination of a motor, a switch for automatically reversing the same upon breaking of the circuit, and automatic means for locking said switch against motion when in its operative position, substantially as described.

In witness whereof I have hereunto set my hand, in the city. county, and State of Ne York, this 23d day of June, 1903.

CHARLES M. CLARK.

In presence of C. W. MACMULLEN, JOHN J. RANAGAN. 

